A rare earth metal complex of bis(aryloxy) functionalized imidazolium salt, its preparation method and application

Abstract

The present invention discloses a bis(aryloxy)-functionalized imidazolium rare earth metal complex, a preparation method thereof and an application thereof. The general formula of the rare earth metal compound is: L3RE2Cl3, and its chemical structural formula is: #imgabs0# where: H2L represents a bis(aryloxy)-functionalized imidazolium cation, and the ligand precursor H2LCl is 1,3-bis(3,5-di-tert-butyl-2-hydroxybenzyl)-imidazolium chloride; RE is a rare earth metal selected from one of yttrium, ytterbium, samarium, neodymium, and lanthanum. The bis(aryloxy)-functionalized imidazolium rare earth metal complex L3RE2Cl3 of the present invention has a clear structure, is simple to prepare, and has a high yield. The present invention provides an application method for the catalytic cycloaddition reaction of alkylene oxide and carbon dioxide by using the rare earth metal complex. The reaction conditions of this method are mild, the substrate adaptability is wide, the experimental process is simple to operate, the post-treatment is convenient, and the safety is high.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalysts, and particularly relates to a preparation method and application of a rare earth metal complex of bis(aryloxy) functionalized imidazolium salt. This case is a divisional application of a patent application with the application number 2022104229688, the application date of April 21, 2022, and the title of "A Rare Earth Metal Complex of Bis(aryloxy) Functionalized Imidazolium Salt and Its Preparation Method and Application". Background Art

[0002] Carbon dioxide is an abundant, renewable and non-toxic C1 resource, but its wide application is restricted due to its own stability and inertness. Cyclic carbonates are important organic compounds with wide application value, and can be used as pharmaceutical and chemical intermediates, synthetic engineering plastics, and aprotic polar solvents, etc. The preparation of cyclic carbonates by the cycloaddition reaction of carbon dioxide and epoxides is a 100% atom-economic reaction. At present, a large number of catalysts have been developed for this reaction, and all of them show good to excellent catalytic activity. These include various metal complexes and ionic liquids, etc.

[0003] Reports on metal complex catalytic systems:

[0004] (1) In 2001, the Nguyen research group prepared a salen chromium complex. In the presence of a cocatalyst 4-dimethylaminopyridine, at 75 °C and a CO2 pressure of 0.7 MPa, the cycloaddition reaction of epoxides and carbon dioxide was catalyzed, and a series of monosubstituted cyclic carbonates were successfully obtained. (See: Paddock, R.L.; Nguyen, S.T. J. Am. Chem. Soc., 2001, 123, 11498-11499.). In 2004, the research group used a chiral salen cobalt complex to catalyze the cycloaddition reaction of epoxides and carbon dioxide. Similarly, 4-dimethylaminopyridine was used as a cocatalyst. At 100 °C and a CO2 pressure of 2 MPa, the conversion of various monosubstituted epoxides was successfully achieved, and for disubstituted epoxides, the corresponding cyclic carbonates could also be obtained in a yield of more than 90%. Although the reaction activity was significantly improved, the reaction conditions were still very harsh and required high temperature and high pressure conditions to proceed smoothly. (See: Paddock, R.L.; Nguyen, S.T. Chem. Commun., 2004, 1622-1623.).

[0005] (2) In 2010, the Kleij research group reported an easily prepared and highly stable salen zinc complex. This complex could smoothly convert monosubstituted epoxides under a CO2 pressure of 1 MPa at 25 °C, and the reaction conditions were relatively mild. (See: Haak, R.M.; Decortes, A.; Escudero-Adan, E.C.; Belmonte, M.M.; Martin, E.; Benet-Buchholz, J.; Kleij, A.W. Inorg. Chem. 2011, 50, 7934 - 7936.). In 2013, this research group used a nitrogen-bridged triaryloxy iron complex as the catalyst and tetrabutylammonium bromide as the cocatalyst to catalyze the cycloaddition reaction of trans-2,3-epoxybutane and CO2 under a CO2 pressure of 1 MPa at 80 °C, and systematically investigated the stereochemical selectivity of the corresponding cyclic carbonate products. Although the above methods can be carried out at relatively low temperatures, they still require the addition of a cocatalyst and a CO2 pressure of 1 MPa, and the reaction operation is complex and has certain potential risks. (See: Whiteoak, C.J.; Martin, E.; Kleij, A.W. Adv. Synth. Catal. 2013, 355, 2233 - 2239.).

[0006] (3) In 2014, the North research group reported a scorpionate-aluminum complex. Under the combined action of this complex and the cocatalyst tetrabutylammonium bromide, the conversion of various monosubstituted epoxides can be achieved at room temperature and atmospheric pressure. For disubstituted epoxides, at room temperature, the CO2 pressure needs to be increased to 10 atmospheres to obtain the target cyclic carbonate. This method realizes the cycloaddition reaction of disubstituted epoxides and CO2, but the operation at 10 atmospheres has special requirements for equipment and there are safety hazards. (See: José A.C.; Carlos, A.M.; Agustín, L.S.; Javier, M.; North, M. and Antonio, O. Catal. Sci. Technol., 2014, 4, 1674–1684.).

[0007] (4) In 2015, the Ema research group synthesized highly active porphyrin double-magnesium complexes and porphyrin triple-magnesium complexes and applied them to the cycloaddition reaction of epoxides and carbon dioxide. Due to the synergistic effect of multiple catalytic sites, the TON and TOF of this catalytic system are as high as 220000 and 46000 h -1Although this method exhibits extremely high catalytic activity, it requires a reaction temperature of 120 °C and a pressure of 17 atmospheres, and has poor substrate adaptability. (See: Maeda, C.; Taniguchi, T.; Ogawa, K. and Ema, T. Angew. Chem. Int. Ed. 2015, 54, 134–138.).

[0008] (5) In 2017, the research group of Yao, Y. M. successfully synthesized and characterized four adducts containing rare earth metal imidazolium salts. It was found that at 1 bar and 90 °C, the ring-opening addition of CO2 and epoxides was completed with only 0.2 mol% of the rare earth metal imidazolium salt adduct, and the catalyst still maintained high catalytic activity after being recycled six times. (See: Zhao, Z. W.; Qin, J.; Zhang, C.; Wang, Y. R.; Yuan, D. and Yao, Y. M. Inorg. Chem. 2017, 56, 4568 - 4575). In 2020, the research group developed a rare earth metal complex with N-methylethylenediamine-bridged triphenol as a ligand. This complex can prepare various monosubstituted cyclic carbonates at room temperature and atmospheric pressure. At the same time, for polysubstituted epoxides, their smooth conversion can also be achieved at atmospheric pressure and a relatively mild temperature of 60 °C. In comparison, the reaction conditions of this catalytic system are relatively mild, but a cocatalyst needs to be added, and the synthesis of the catalyst is difficult due to the low yield of the ligand precursor synthesis. (See: Xin, X.; Shan, H. W.; Tian, T.; Wang, Y. R.; Yuan, D.; You, H. P. and Yao, Y. M. ACS Sustainable Chem. Eng. 2020, 8, 13185 - 13194).

[0009] Reports on ionic liquid catalytic systems:

[0010] (1) In 2016, the research group of Sun, J. M. used a urea-functionalized imidazolium salt ionic liquid. This ionic liquid is easy to prepare, has good stability, and exhibits excellent carbon dioxide capture ability, and can activate carbon dioxide in a 1:2 molar ratio. However, the reaction needs to be carried out at 130 °C and a carbon dioxide pressure of 15 atmospheres for 3 hours to achieve the conversion of various monosubstituted epoxides. (See: Liu, M.; Liang, L.; Li, X.; Gao, X. and Sun, J. M. Green Chem. 2016, 18, 2851–2863).

[0011] (2) In 2018, the research group of Gao, G. H. used a bimolecular cooperative catalytic system composed of imidazolium ionic liquid and organic base to achieve the cycloaddition reaction of carbon dioxide and epoxides at one atmosphere and 80 °C. Compared with the single system, the catalytic activity was significantly improved, and high-yield cyclic carbonates could be obtained under milder conditions. (See: Ji, L.; Luo, Z.; Zhang, Y.; Wang, R.; Ji, Y.; Xia, F.; Gao, G. H. Mol. Catal. 2018, 446, 124–130).

[0012] (2) In 2019, the research group of Zhang, X. P. developed a bifunctional protonic ionic liquid. The alkoxy anions and strong hydrogen bond interactions in the ionic liquid activated carbon dioxide and epoxides respectively, and cyclic carbonates could be prepared in the presence of carbon dioxide at one atmosphere and 30 °C for 6 hours without the participation of a cocatalyst, with high yields. The conditions of this catalytic system were mild, but the substrate applicability was poor. (See: Meng, X.; Ju, Z.; Zhang, S.; Liang, X.; Nicolas von Solms; Zhang, X. P. Green Chem. 2019, 21, 3456–3463).

[0013] Although a variety of different catalytic systems have been developed for the cycloaddition reaction of epoxides and carbon dioxide, the reaction conditions have been greatly optimized and can be carried out under mild conditions. However, most catalysts still have disadvantages such as large dosage, poor substrate adaptability, and the need for the co-action of cocatalysts. Therefore, it is still of great significance to find a single-component catalyst system with simple raw material sources, small dosage, good universality, and capable of efficiently synthesizing cyclic carbonate compounds. Summary of the Invention

[0014] To solve the above technical problems, the present invention provides the synthesis of a bis(aryloxy)functionalized imidazolium rare earth metal complex, which can be used as a single-component catalyst to catalyze the cycloaddition reaction of epoxides and carbon dioxide to prepare cyclic carbonate compounds. This complex is easy to prepare, shows high catalytic activity without adding a cocatalyst, has good regioselectivity, wide substrate adaptability, and good yields.

[0015] The first object of the present invention is to provide the application of a precatalyst composed of a bis(aryloxy)functionalized imidazolium H2LCl and RE[N(SiMe3)2]3 in the in-situ catalytic cycloaddition reaction of epoxides and carbon dioxide.

[0016] In one embodiment of the present invention, the method of the application includes the following steps:

[0017] (1) Under an inert gas atmosphere, RE[N(SiMe3)2]3 and a bis(aryloxy)-functionalized imidazolium salt are mixed, an epoxide is added, and after introducing carbon dioxide gas to completely displace the inert gas, the mixture is stirred and heated for reaction; wherein, RE is yttrium, ytterbium, samarium, neodymium or lanthanum;

[0018] (2) After the reaction in step (1) is completed, a quenching agent is added to terminate the reaction, and the target product, a cyclic carbonate compound, is obtained.

[0019] In one embodiment of the present invention, the structural formula of the bis(aryloxy)-functionalized imidazolium salt is as follows:

[0020]

[0021] In one embodiment of the present invention, in step (1), the temperature of the heating reaction is 80 - 110 °C, and the reaction time is 12 - 24 hours.

[0022] In one embodiment of the present invention, in step (1), the molar ratio of the epoxide, the ligand precursor and RE[N(SiMe3)2]3 is 200 - 50:2 - 1:1.

[0023] The second object of the present invention is to provide an application of a rare earth metal complex of a bis(aryloxy)-functionalized imidazolium salt in the cycloaddition reaction of an epoxide with carbon dioxide. The rare earth metal complex of the imidazolium salt is obtained by reacting the bis(aryloxy)-functionalized imidazolium salt with RE[N(SiMe3)2]3, and the structural formula is as follows:

[0024]

[0025] Wherein, RE is yttrium, ytterbium, samarium, neodymium or lanthanum.

[0026] In one embodiment of the present invention, the rare earth metal complex of the imidazolium salt is prepared by the following method:

[0027] RE[N(SiMe3)2]3 is dissolved in an organic solvent to obtain a solution of RE[N(SiMe3)2]3, and an H2LCl solution is added dropwise, and the reaction is carried out for 12 - 18 hours, and after purification and concentration, the rare earth metal complex of the imidazolium salt is obtained;

[0028] Wherein, RE is yttrium, ytterbium, samarium, neodymium or lanthanum.

[0029] In one embodiment of the present invention, H2LCl in the H2LCl solution is prepared by the following method: Dissolve 2,4-di-tert-butyl-6-chloromethylphenol in an organic solvent, add sodium bicarbonate and imidazole, and react at 80-110 °C for 12-24 hours. After the reaction is completed, perform solid-liquid separation to obtain the solid phase, which is the H2LCl.

[0030] In one embodiment of the present invention, the molar ratio of 2,4-di-tert-butyl-6-chloromethylphenol, sodium bicarbonate, and imidazole is 2.08:1:1.

[0031] In one embodiment of the present invention, the specific application method steps are as follows: Under an inert gas environment, add an alkylene oxide to the rare earth metal complex of bis(aryloxy) functionalized imidazolium salt. After introducing carbon dioxide gas to displace all the inert gas, stir and heat. After the reaction is completed, add a quenching agent to terminate the reaction to obtain a cyclic carbonate compound.

[0032] In one embodiment of the present invention, the molar ratio of the alkylene oxide to the rare earth metal complex of bis(aryloxy) functionalized imidazolium salt is 400-100:1.

[0033] In one embodiment of the present invention, the conditions for the heating reaction are: the heating temperature is 80-110 °C, and the reaction time is 12-24 hours.

[0034] The above technical solutions of the present invention have the following advantages compared with the prior art:

[0035] 1. The rare earth metal complex of bis(aryloxy) functionalized imidazolium salt used in the present invention has a clear structure, a simple synthesis method, a high yield, simple separation and purification, and can achieve single-component catalysis without a cocatalyst. First, the reactant alkylene oxide coordinates with the central metal RE1 through an oxygen atom, the RE1-μ-Cl bond is broken, but Cl is still connected to RE2 and is weakly connected to the imidazole H through a hydrogen bond at the same time, which is intermediate A. Cl attacks the alkylene oxide to open the ring to form a C-Cl bond, and at the same time the oxygen anion of the alkylene oxide is weakly coordinated with RE2, which is intermediate B. The oxygen anion of the alkylene oxide attacks the carbon of CO2 in the system to obtain a carbonate ion, which is intermediate C. Then the carbonate ion attacks to close the ring to form a cyclic ester, and at the same time the C-Cl bond is broken and the Cl ion leaves. At this time, the reactant alkylene oxide attacks RE1 to regenerate A, and at the same time releases the product cyclic carbonate to complete the catalytic cycle (see Figure 1 ).

[0036] 2. The catalyst disclosed in the present invention has high activity. The amount of the catalyst used is 0.5 mol% of the reactant alkylene oxide, and the product yield is high. The use of less catalyst is also beneficial to the purification of the product.

[0037] 3. In the preparation method disclosed by the present invention, the raw materials are easily available, the reaction conditions are mild, the reaction substrates have a wide universality, and it can efficiently catalyze the reaction of alkylene oxide and carbon dioxide; the reaction time is short, the yield of the target product is high, and the reaction operation process is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to make the content of the present invention easier to be clearly understood, the following further details the present invention according to specific embodiments of the present invention in combination with the drawings, where

[0039] Figure 1 is the catalytic mechanism diagram of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] The following further describes the present invention in combination with the drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the embodiments cited do not limit the present invention.

[0041] Example 1: Preparation of L3Y2Cl3

[0042] (1) Preparation of H2LCl

[0043] Synthesis of 1,3-bis(3,5-di-tert-butyl-2-hydroxybenzyl)-imidazolium chloride: Weigh a certain molar amount of 2,4-di-tert-butyl-6-chloromethylphenol into a flask, slowly add toluene to dissolve it with stirring, weigh sodium bicarbonate and imidazole in a molar ratio of 1:2, add them to the reaction vessel in sequence, and then place the whole device in a constant temperature stirrer at 90 °C for reaction for 24 hours. After the reaction is completed, cool to room temperature, add an appropriate amount of ethyl acetate, and a large amount of precipitate will precipitate. Filter by suction, wash the solid with dry ethyl acetate until it is colorless, and dry it to obtain the ligand precursor H2LCl: 1,3-bis(3,5-di-tert-

[0044] 2-hydroxybenzyl)-imidazolium chloride, with a yield of 85%. NMR data: 1 H NMR(400MHz,DMSO): δ9.02(s,1H,NCHN); 8.80(s,2H,ArOH); 7.70-7.69(d,J = 1.6Hz,2H,NCHCHN); 7.23-7.22(d,J = 2.4Hz,2H,ArH); 7.08-7.07(d,J = 2.4Hz,2H,ArH); 5.50(s,4H,CH2); 1.34(s,18H,CH3); 1.21(s,18H,CH3).

[0045] (2) Preparation of L3Y2Cl3

[0046] At room temperature, in a reaction flask that has been treated under anhydrous and anaerobic conditions and is protected by argon, Y[N(SiMe3)2]3 is added and dissolved in tetrahydrofuran. In another empty flask that has also been treated under anhydrous and anaerobic conditions and is in an argon atmosphere, 1.5 equivalents of the ligand precursor H2LCl are weighed out, added with tetrahydrofuran, and the ligand suspension is slowly added to the reaction flask containing the clear solution of Y[N(SiMe3)2]3. The solution gradually becomes turbid, and after stirring for about 5 - 10 minutes, the solution gradually becomes clear, and the reaction continues for 12 - 18 hours.

[0047] (3) After the reaction is completed, the solvent is removed completely, washed with n - hexane, then added with tetrahydrofuran to dissolve the solid, centrifuged, the upper clear liquid is taken, concentrated, a small amount of n - hexane is added, and left standing at room temperature to precipitate crystals, which are the rare - earth metal complex L3Y2Cl3 of bis - aryloxy - functionalized imidazolium salt, and the reaction yield is 88%. NMR data: 1 H NMR(400MHz,Tol - d8): δ9.53(s,3H,NCHN); 7.33(s,6H,NCHCHN); 6.81(s,6H,ArH); 6.26 - 7.23(d,J = 13.0Hz,2H,CH2); 5.70(s,6H,ArH); 3.62 - 3.60(d,J = 11.6Hz,6H,CH2); 1.28(s,54H,CH3); 1.22(s,54H,CH3). Infrared absorption spectrum data (ν, cm -1 ): 2951(s), 2898(s), 2863.60(s), 1467(s), 1438(s), 1410(s), 1389(s), 1359(s), 1290(s), 1274(s), 1236(s), 1201(s), 1160(s), 1128(s), 1100(s), 1065(s), 1050(s), 1021(s), 910(s), 877(s), 834(s), 815(s), 794(s), 745(s), 729(s), 643(s), 625(s), 614(s), 526(s), 430(s).

[0048] Example 2: Preparation of L3Yb2Cl3

[0049] Steps (1), (2) and (3) of this Example 2 are the same as those of Example 1. In step (2), Yb[N(SiMe3)2]3 was added into a reaction flask that had been treated under anhydrous and anaerobic conditions and protected by argon, and other operations were exactly the same. After the reaction ended, after post-treatment, it was dissolved in tetrahydrofuran, centrifuged, the upper clear liquid was taken, concentrated, and left standing at room temperature until crystals precipitated, which was the rare earth metal complex L3Yb2Cl3 of bis(aryloxy) functionalized imidazolium salt, and the reaction yield was 85%. Infrared absorption spectrum data (ν, cm -1 ): 2950(s), 2898(s), 2861(s), 1465(s), 1438(s), 1411(s), 1388(s), 1359(s), 1292(s), 1275(s), 1236(s), 1201(s), 1162(s), 1132(s), 1098.79(s), 1062(s), 1029(s), 909(s), 876(s), 834(s), 812(s), 792(s), 745(s), 726(s), 713(s), 668(s), 643(s), 626(s), 613(s), 592(s), 555(s), 547(s), 525(s), 497(s), 487(s), 479(s), 468(s), 449(s), 425(s).

[0050] Example 3: Preparation of L3Sm2Cl3

[0051] Steps (1), (2) and (3) of this Example 3 are the same as those of Example 1. In step (2), Sm[N(SiMe3)2]3 was added into a reaction flask that had been treated under anhydrous and anaerobic conditions and protected by argon, and other operations were exactly the same. After the reaction ended, after post-treatment, it was dissolved in tetrahydrofuran, centrifuged, the upper clear liquid was taken, concentrated, and left standing at room temperature until crystals precipitated, which was the rare earth metal complex L3Sm2Cl3 of bis(aryloxy) functionalized imidazolium salt, and the reaction yield was 70%. Infrared absorption spectrum data (ν, cm -1 ): 2951(s), 2903(s), 2865(s), 1604(w), 1547(w), 1464(s), 1438(s), 1411(s), 1388(s), 1359(s), 1329(s), 1292(s), 1275(s), 1236(s), 1201(s), 1162(s), 1131(s), 1098(s), 1062(s), 1024(s), 960(s), 910(s), 875(s), 832(s), 812(s), 792(s), 743(s), 667(s), 643(s), 626(s).

[0052] Example 4: Preparation of L3Nd2Cl3

[0053] Steps (1), (2), and (3) of this Example 2 are the same as those of Example 1. In step (2), Nd[N(SiMe3)2]3 was added to a reaction flask that had been treated under anhydrous and anaerobic conditions and protected by argon, and other operations were exactly the same. After the reaction ended, after post-treatment, it was dissolved in tetrahydrofuran and centrifuged. The upper clear liquid was taken, a small amount of toluene was added, concentrated, and left standing at room temperature until crystals precipitated, which was the rare earth metal complex L3Nd2Cl3 of bis(aryloxy)-functionalized imidazolium salt. The reaction yield was 65%. Infrared absorption spectral data (ν, cm -1 ) : 2950(s), 2903(s), 2865(s), 1604(w), 1573(w), 1543(s), 1464(s), 1437(s), 1411(s), 1388(s), 1359(s), 1330(s), 1274(s), 1235(s), 1200(s), 1162(s), 1128(s), 1097(s), 1066(s), 1024(s), 961(s), 909(s), 877(s), 831(s), 812(s), 792(s), 742(s), 727(s), 642(s), 625(s), 611(s).

[0054] Example 5: Preparation of L3La2Cl3

[0055] Steps (1), (2), and (3) of this Example 2 are the same as those of Example 1. In step (2), La[N(SiMe3)2]3 was added to a reaction flask that had been treated under anhydrous and anaerobic conditions and protected by argon, and other operations were exactly the same. After the reaction ended, after post-treatment, it was dissolved in tetrahydrofuran and centrifuged. The upper clear liquid was taken, a small amount of toluene was added, concentrated, and left standing at room temperature until crystals precipitated, which was the rare earth metal complex L3La2Cl3 of bis(aryloxy)-functionalized imidazolium salt, and the reaction yield was 55%. NMR characterization data 1 1H NMR (400 MHz, Tol-d8): δ 9.74 (s, 3H, NCHN); 7.56 - 7.55 (d, 6H, NCHCHN); 6.97 - 6.96 (d, J = 2.56 Hz, 6H, ArH); 6.35 - 6.32 (d, J = 13.16 Hz, 2H, CH2); 5.78 (d, J = 1.52 Hz, 6H, ArH); 3.88 - 3.77 (d, J = 13.08 Hz, 6H, CH2); 1.58 (s, 54H, CH3); 1.37 (s, 54H, CH3). Infrared absorption spectral data (ν, cm -1):951(s), 2902(s), 2864(s), 1466(s), 1436(s), 1411(s), 1358(s), 1275(s), 1233(s), 1198(s), 1161(s), 1128(s), 1097(s), 1022(s), 905(s), 876(s), 830(s), 791(s), 736(s), 695(s), 643(s), 618.93(s), 521.31(s), 464(s), 424(s). The above data prove the successful preparation of the target compound.

[0056] Comparative Example 1

[0057] In a reaction flask that has been treated with anhydrous and anaerobic conditions and protected by an inert gas, add 0.0249 grams (4.38×10 -5 moles) of Y[N(SiMe3)2]3 and 0.0346 grams (6.57×10 -5 moles) of H2LCl, then inject 0.5 milliliters (4.38×10 -3 moles) of styrene oxide using a syringe. After replacing all the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, stir the entire apparatus at 90°C for 20 hours. After cooling to room temperature, add an internal standard, stir for 10 - 15 minutes, then take out 5 drops of the mixture with a syringe to measure the NMR. The NMR yield is 82%.

[0058] Comparative Example 2:

[0059] 0.5 mol% of L3Y2Cl3 catalyzes the cycloaddition reaction of styrene oxide and carbon dioxide at 90°C under atmospheric pressure:

[0060] In a reaction flask that has been treated with anhydrous and anaerobic conditions and protected by an inert gas, add 0.0039 grams (2.19×10 -6 moles) of L3Y2Cl3, then inject 0.5 milliliters (4.38×10 -3 moles) of styrene oxide using a syringe. After replacing all the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, stir the entire apparatus at 90°C for 16 hours. After cooling to room temperature, add 5 mL of deionized water to quench the reaction, transfer the mixture to a separatory funnel, extract with ethyl acetate, separate the layers, dry over anhydrous sodium sulfate, filter, and perform flash column chromatography to obtain a pure product. Calculate the yield to be 80%.

[0061] By comparing the above two examples, it was found that when the catalyst dosage of complex L3Y2Cl3 was 0.5 mol% and other conditions were the same, the catalytic effect was basically the same as that of in-situ catalysis. Therefore, the solid structure of this metal complex is very likely to be the structure of the catalyst during the reaction process.

[0062] Application Example

[0063] Application Example 1: The cycloaddition reaction of styrene oxide and carbon dioxide was catalyzed by 1 mol% of La[N(SiMe3)2]3 and 1.5 mol% of H2LCl at 90 °C under atmospheric pressure:

[0064] In a reaction flask that had been treated for anhydrous and anaerobic conditions and was protected by an inert gas, 0.0271 g (4.38×10 -5 mol) of La[N(SiMe3)2]3 and 0.0346 g (6.57×10 -5 mol) of H2LCl were added. Then, 0.5 mL (4.38×10 -3 mol) of styrene oxide was injected using a syringe. After replacing all the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, the entire device was stirred and reacted at 90 °C for 16 hours. After cooling to room temperature, an internal standard was added. After stirring for 10 - 15 min, 5 drops of the mixture were taken out using a syringe for NMR measurement, and the NMR yield was 35%. NMR data: 1 H NMR(400MHz,CDCl3)δ7.44 - 7.41(m,3H),7.36 - 7.34(m,2H),5.70 - 5.65(t,J = 8.0Hz,1H),4.81 - 4.77(t,J = 8.4Hz,1H),4.35 - 4.31(dd,J = 8.6,7.9Hz,1H).

[0065] Application Example 2: The cycloaddition reaction of styrene oxide and carbon dioxide was catalyzed by 1 mol% of Nd[N(SiMe3)2]3 and 1.5 mol% of H2LCl at 90 °C under atmospheric pressure:

[0066] In a reaction flask that had been treated for anhydrous and anaerobic conditions and was protected by an inert gas, 0.0274 g (4.38×10 -5 mol) of Nd[N(SiMe3)2]3 and 0.0346 g (6.57×10 -5 mol) of H2LCl were added. Then, 0.5 mL (4.38×10 -3Styrene oxide (1 mol), after replacing all the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, the entire apparatus was stirred at 90 °C for 16 hours. After cooling to room temperature, an internal standard was added, and after stirring for 10 - 15 min, 5 drops of the mixture were taken out with a syringe to prepare the NMR, and the NMR yield was 68%.

[0067] Application Example 3: The cycloaddition reaction of styrene oxide and carbon dioxide was catalyzed by 1 mol% of Sm[N(SiMe3)2]3 and 1.5 mol% of H2LCl at 90 °C under atmospheric pressure:

[0068] In a reaction flask that had been treated with anhydrous and anaerobic conditions and protected by an inert gas, 0.0276 g (4.38×10 -5 mol) of Sm[N(SiMe3)2]3 and 0.0346 g (6.57×10 -5 mol) of H2LCl were added, and then 0.5 mL (4.38×10 -3 mol) of styrene oxide was injected with a syringe. After replacing all the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, the entire apparatus was stirred at 90 °C for 16 hours. After cooling to room temperature, an internal standard was added, and after stirring for 10 - 15 min, 5 drops of the mixture were taken out with a syringe to measure the NMR, and the NMR yield was 62%.

[0069] Application Example 4: The cycloaddition reaction of styrene oxide and carbon dioxide was catalyzed by 1 mol% of Eu[N(SiMe3)2]3 and 1.5 mol% of H2LCl at 90 °C under atmospheric pressure:

[0070] In a reaction flask that had been treated with anhydrous and anaerobic conditions and protected by an inert gas, 0.0277 g (4.38×10 -5 mol) of Eu[N(SiMe3)2]3 and 0.0346 g (6.57×10 -5 mol) of H2LCl were added, and then 0.5 mL (4.38×10 -3 mol) of styrene oxide was injected with a syringe. After replacing all the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, the entire apparatus was stirred at 90 °C for 16 hours. After cooling to room temperature, an internal standard was added, and after stirring for 10 - 15 min, 5 drops of the mixture were taken out with a syringe to prepare the NMR, and the NMR yield was 78%.

[0071] Application Example 5: The cycloaddition reaction of styrene oxide and carbon dioxide was catalyzed by 1 mol% of Yb[N(SiMe3)2]3 and 1.5 mol% of H2LCl at 90 °C under atmospheric pressure:

[0072] In a reaction flask that has been treated to be anhydrous and anaerobic and is protected by an inert gas, add 0.0286 g (4.38×10 -5 mol) of Yb[N(SiMe3)2]3 and 0.0346 g (6.57×10 -5 mol) of H2LCl. Then, inject 0.5 mL (4.38×10 -3 mol) of styrene oxide into the flask using a syringe. After completely replacing the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, stir the entire apparatus at 90 °C for 16 hours. After cooling to room temperature, add an internal standard, stir for 10 - 15 min, then take out 5 drops of the mixture with a syringe to prepare the NMR. The NMR yield is 80%.

[0073] Application Example 6: The cycloaddition reaction of styrene oxide and carbon dioxide catalyzed by 1 mol% of Y[N(SiMe3)2]3 and 1.5 mol% of H2LCl at 90 °C under atmospheric pressure:

[0074] In a reaction flask that has been treated to be anhydrous and anaerobic and is protected by an inert gas, add 0.0249 g (4.38×10 -5 mol) of Y[N(SiMe3)2]3 and 0.0346 g (6.57×10 -5 mol) of H2LCl. Then, inject 0.5 mL (4.38×10 -3 mol) of styrene oxide into the flask using a syringe. After completely replacing the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, stir the entire apparatus at 90 °C for 16 hours. After cooling to room temperature, add an internal standard, stir for 10 - 15 min, then take out 5 drops of the mixture with a syringe to prepare the NMR. The NMR yield is 82%.

[0075] Application Example 7: The cycloaddition reaction of styrene oxide and carbon dioxide catalyzed by 1 mol% of Y[N(SiMe3)2]3 and 1 mol% of H2LCl at 90 °C under atmospheric pressure:

[0076] In a reaction flask that has been treated to be anhydrous and anaerobic and is protected by an inert gas, add 0.0249 g (4.38×10 -5 mol) of Y[N(SiMe3)2]3 and 0.0231 g (4.38×10 -5 mol) of H2LCl. Then, inject 0.5 mL (4.38×10 -3 mol) of styrene oxide into the flask using a syringe. After completely replacing the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, stir the entire apparatus at 90 °C for 16 hours. After cooling to room temperature, add an internal standard, stir for 10 - 15 min, then take out 5 drops of the mixture with a syringe to prepare the NMR. The NMR yield is 65%.

[0077] Application Example 8: 1 mol% of Y[N(SiMe3)2]3 and 2 mol% of H2LCl catalyze the cycloaddition reaction of styrene and carbon dioxide at 90 °C under atmospheric pressure:

[0078] In a reaction flask that has been treated for anhydrous and anaerobic conditions and protected by an inert gas, add 0.0249 g (4.38×10 -5 mol) of Y[N(SiMe3)2]3 and 0.0461 g (8.76×10 -5 mol) of H2LCl. Then, inject () styrene oxide using a syringe. After completely displacing the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, stir the entire apparatus at 90 °C for 16 hours. After cooling to room temperature, add an internal standard, stir for 10 - 15 min, then take out 5 drops of the mixture with a syringe to prepare the NMR. The NMR yield is 75%.

[0079] Application Example 9: 0.5 mol% of Y[N(SiMe3)2]3 and 0.75 mol% of H2LCl catalyze the cycloaddition reaction of styrene and carbon dioxide at 90 °C under atmospheric pressure:

[0080] In a reaction flask that has been treated for anhydrous and anaerobic conditions and protected by an inert gas, add 0.0125 g (2.19×10 -5 mol) of Y[N(SiMe3)2]3 and 0.0173 g (3.28×10 -5 mol) of H2LCl. Then, inject 0.5 mL (4.38×10 -3 mol) of styrene oxide using a syringe. After completely displacing the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, stir the entire apparatus at 90 °C for 16 hours. After cooling to room temperature, add an internal standard, stir for 10 - 15 min, then take out 5 drops of the mixture with a syringe to prepare the NMR. The NMR yield is 46%.

[0081] Application Example 10: 2 mol% of Y[N(SiMe3)2]3 and 3 mol% of H2LCl catalyze the cycloaddition reaction of styrene and carbon dioxide at 90 °C under atmospheric pressure:

[0082] In a reaction flask that has been treated for anhydrous and anaerobic conditions and protected by an inert gas, add 0.0498 g (8.76×10 -5 mol) of Y[N(SiMe3)2]3 and 0.0692 g (1.31×10 -4 mol) of H2LCl. Then, inject 0.5 mL (4.38×10 -3Styrene oxide (1 mol), after replacing all the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, the entire apparatus was stirred at 90 °C for 16 hours. After cooling to room temperature, an internal standard was added, and after stirring for 10 - 15 min, 5 drops of the mixture were taken out with a syringe to prepare the NMR, and the NMR yield was 82%.

[0083] Application Example 11: The cycloaddition reaction of styrene oxide and carbon dioxide was catalyzed by 1 mol% of Y[N(SiMe3)2]3 and 1.5 mol% of H2LCl at 80 °C under atmospheric pressure:

[0084] In a reaction flask that had been treated with anhydrous and anaerobic conditions and protected by an inert gas, 0.0249 g (4.38×10 -5 mol) of Y[N(SiMe3)2]3 and 0.0346 g (6.57×10 -5 mol) of H2LCl were added, and then 0.5 mL (4.38×10 -3 mol) of styrene oxide was injected with a syringe. After replacing all the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, the entire apparatus was stirred at 80 °C for 16 hours. After cooling to room temperature, an internal standard was added, and after stirring for 10 - 15 min, 5 drops of the mixture were taken out with a syringe to prepare the NMR, and the NMR yield was 56%.

[0085] Application Example 12: The cycloaddition reaction of styrene oxide and carbon dioxide was catalyzed by 1 mol% of Y[N(SiMe3)2]3 and 1.5 mol% of H2LCl at 100 °C under atmospheric pressure:

[0086] In a reaction flask that had been treated with anhydrous and anaerobic conditions and protected by an inert gas, 0.0249 g (4.38×10 -5 mol) of Y[N(SiMe3)2]3 and 0.0346 g (6.57×10 -5 mol) of H2LCl were added, and then 0.5 mL (4.38×10 -3 mol) of styrene oxide was injected with a syringe. After replacing all the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, the entire apparatus was stirred at 100 °C for 16 hours. After cooling to room temperature, an internal standard was added, and after stirring for 10 - 15 min, 5 drops of the mixture were taken out with a syringe to prepare the NMR, and the NMR yield was 50%.

[0087] Application Example 13: The cycloaddition reaction of styrene oxide and carbon dioxide was catalyzed by 1 mol% of Y[N(SiMe3)2]3 and 1.5 mol% of H2LCl at 110 °C under atmospheric pressure:

[0088] In a reaction flask that has been treated to be anhydrous and anaerobic and is protected by an inert gas, 0.0249 g (4.38×10 -5 mol) of Y[N(SiMe3)2]3 and 0.0346 g (6.57×10 -5 mol) of H2LCl are added. Then, 0.5 mL (4.38×10 -3 mol) of styrene oxide is injected using a syringe. After completely displacing the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, the entire apparatus is stirred and reacted at 110 °C for 16 hours. After cooling to room temperature, an internal standard is added. After stirring for 10 - 15 min, 5 drops of the mixture are taken out using a syringe to prepare the NMR. The NMR yield is 45%.

[0089] Application Example 14: The cycloaddition reaction of styrene oxide and carbon dioxide catalyzed by 1 mol% of Y[N(SiMe3)2]3 and 1.5 mol% of H2LCl at 90 °C under atmospheric pressure:

[0090] In a reaction flask that has been treated to be anhydrous and anaerobic and is protected by an inert gas, 0.0249 g (4.38×10 -5 mol) of Y[N(SiMe3)2]3 and 0.0346 g (6.57×10 -5 mol) of H2LCl are added. Then, 0.5 mL (4.38×10 -3 mol) of styrene oxide is injected using a syringe. After completely displacing the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, the entire apparatus is stirred and reacted at 90 °C for 12 hours. After cooling to room temperature, an internal standard is added. After stirring for 10 - 15 min, 5 drops of the mixture are taken out using a syringe to prepare the NMR. The NMR yield is 71%.

[0091] Application Example 15: The cycloaddition reaction of styrene oxide and carbon dioxide catalyzed by 1 mol% of Y[N(SiMe3)2]3 and 1.5 mol% of H2LCl at 90 °C under atmospheric pressure:

[0092] In a reaction flask that has been treated to be anhydrous and anaerobic and is protected by an inert gas, 0.0249 g (4.38×10 -5 mol) of Y[N(SiMe3)2]3 and 0.0346 g (6.57×10 -5 mol) of H2LCl are added. Then, 0.5 mL (4.38×10 -3 mol) of styrene oxide is injected using a syringe. After completely displacing the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, the entire apparatus is stirred and reacted at 90 °C for 24 hours. After cooling to room temperature, an internal standard is added. After stirring for 10 - 15 min, 5 drops of the mixture are taken out using a syringe to prepare the NMR. The NMR yield is 77%.

[0093] Application Example 16: 0.5 mol% of L3Y2Cl3 catalyzes the cycloaddition reaction of 1,2-epoxybutane and carbon dioxide at 90 °C under atmospheric pressure:

[0094] In a reaction flask that has been treated for anhydrous and anaerobic conditions and protected by an inert gas, add 0.0039 g (2.19×10 -6 mol) of L3Y2Cl3, and then inject 0.38 mL (4.38×10 -3 mol) of 1,2-epoxybutane using a syringe. After completely displacing the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, stir the entire apparatus at 90 °C for 16 hours. After cooling to room temperature, add 5 mL of deionized water to quench the reaction. Transfer the mixture to a separatory funnel, extract with ethyl acetate, separate the layers, dry over anhydrous sodium sulfate, filter, and perform flash column chromatography to obtain a pure product. Calculate the yield to be 96%. NMR data: 1 H NMR (400 MHz, CDCl3) δ 4.64 - 4.57 (m, 1H), 4.48 - 4.44 (t, J = 8.2 Hz, 1H), 4.03 - 3.99 (dd, J = 8.4, 7.0 Hz, 1H), 1.78 - 1.63 (m, 2H), 0.95 - 0.91 (t, J = 7.5 Hz, 3H).

[0095] Application Example 17: 0.5 mol% of L3Y2Cl3 catalyzes the cycloaddition reaction of 1,2-epoxydodecane and carbon dioxide at 90 °C under atmospheric pressure:

[0096] In a reaction flask that has been treated for anhydrous and anaerobic conditions and protected by an inert gas, add 0.0039 g (2.19×10 -6 mol) of L3Y2Cl3, and then inject 0.96 mL (4.38×10 -3 mol) of 1,2-epoxydodecane using a syringe. After completely displacing the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, stir the entire apparatus at 90 °C for 16 hours. After cooling to room temperature, add 5 mL of deionized water to quench the reaction. Transfer the mixture to a separatory funnel, extract with ethyl acetate, separate the layers, dry over anhydrous sodium sulfate, filter, and perform flash column chromatography to obtain a pure product. Calculate the yield to be 83%. NMR data: 11H NMR (400 MHz, CDCl3) δ 4.70 - 4.63 (qd, J = 7.5, 5.4 Hz, 1H), 4.51 - 4.47 (m, 1H), 4.04 - 4.01 (dd, J = 8.4, 7.2 Hz, 1H), 1.79 - 1.73 (m, 1H), 1.68 - 1.60 (m, 1H), 1.23 (s, 15H), 0.86 - 0.82 (t, J = 6.9 Hz, 3H).

[0097] Application Example 18: 0.5 mol% of L3Y2Cl3 catalyzes the cycloaddition reaction of 1,2 - epoxy - 5 - hexene and carbon dioxide at 90 °C under atmospheric pressure:

[0098] In a reaction flask that has been treated for anhydrous and anaerobic conditions and is protected by an inert gas, 0.0039 g (2.19×10 -6 moles) of L3Y2Cl3 is added, and then 0.49 mL (4.38×10 -4 moles) of 1,2 - epoxy - 5 - hexene is injected using a syringe. After replacing all the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, the entire apparatus is stirred and reacted at 90 °C for 16 hours. After cooling to room temperature, 5 mL of deionized water is added to quench the reaction. The mixture is transferred entirely into a separatory funnel, extracted with ethyl acetate, separated, dried over anhydrous sodium sulfate, filtered, and purified by flash column chromatography to obtain the pure product. The yield is calculated to be 80%. NMR data: 1 1H NMR (400 MHz, CDCl3) δ 5.77 - 5.67 (ddt, J = 17.0, 10.2, 6.7 Hz, 1H), 5.03 - 4.95 (m, 2H), 4.71 - 4.64 (qd, J = 7.8, 5.2 Hz, 1H), 4.50 - 4.46 (m, 1H), 4.04 - 4.00 (dd, J = 8.5, 7.2 Hz, 1H), 2.22 - 2.05 (m, 2H), 1.88 - 1.80 (dtd, J = 14.1, 8.1, 5.9 Hz, 1H), 1.76 - 1.67 (m, 1H).

[0099] Application Example 19: 0.5 mol% of L3Y2Cl3 catalyzes the cycloaddition reaction of epichlorohydrin and carbon dioxide at 90 °C under atmospheric pressure:

[0100] In a reaction flask that has been treated for anhydrous and anaerobic conditions and is protected by an inert gas, 0.0039 g (2.19×10 -6 moles) of L3Y2Cl3 is added, and then 0.34 mL (4.38×10 -4Epichlorohydrin (0.5 mol). After replacing all the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, the entire apparatus was stirred at 90 °C for 16 hours. After cooling to room temperature, 5 mL of deionized water was added to quench the reaction. The mixture was transferred to a separatory funnel, extracted with ethyl acetate, separated, dried over anhydrous sodium sulfate, filtered, and purified by flash column chromatography to obtain the pure product. The yield was calculated to be 93%. NMR data 1 H NMR (400 MHz, CDCl3) δ 5.00 - 4.94 (m, 1H), 4.60 - 4.55 (t, J = 8.6 Hz, 1H), 4.40 - 4.37 (dd, J = 8.9, 5.7 Hz, 1H), 3.81 - 3.77 (dd, J = 12.2, 5.2 Hz, 1H), 3.73 - 3.69 (dd, J = 12.2, 3.7 Hz, 1H).

[0101] Application Example 20: 0.5 mol% of L3Y2Cl3 catalyzed the cycloaddition reaction of epibromohydrin and carbon dioxide at 90 °C under atmospheric pressure:

[0102] In a reaction flask that had been treated with anhydrous and anaerobic conditions and protected by an inert gas, 0.0039 g (2.19×10 -6 mol) of L3Y2Cl3 was added, and then 0.36 mL (4.38×10 -4 mol) of epibromohydrin was injected with a syringe. After replacing all the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, the entire apparatus was stirred at 90 °C for 16 hours. After cooling to room temperature, 5 mL of deionized water was added to quench the reaction. The mixture was transferred to a separatory funnel, extracted with ethyl acetate, separated, dried over anhydrous sodium sulfate, filtered, and purified by flash column chromatography to obtain the pure product. The yield was calculated to be 95%. NMR data: 1 H NMR (400 MHz, CDCl3) δ 4.97 - 4.93 (m, 1H), 4.58 - 4.54 (t, J = 8.6 Hz, 1H), 4.31 - 4.27 (dd, J = 8.9, 5.9 Hz, 1H), 3.62 - 3.58 (dd, J = 11.4, 5.4 Hz, 1H), 3.56 - 3.52 (dd, J = 11.1, 4.2 Hz, 1H).

[0103] Application Example 21: 0.5 mol% of L3Y2Cl3 catalyzed the cycloaddition reaction of 2-(methoxymethyl)oxirane and carbon dioxide at 90 °C under atmospheric pressure:

[0104] In a reaction flask that had been treated with anhydrous and anaerobic conditions and protected by an inert gas, 0.0039 g (2.19×10 -6mol) of L3Y2Cl3, and then 0.39 mL (4.38×10 -4 mol) of 2-(methoxymethyl)oxirane was injected with a syringe. After replacing all the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, the entire apparatus was stirred at 90 °C for 16 hours. After cooling to room temperature, 5 mL of deionized water was added to quench the reaction. The mixture was transferred to a separatory funnel, extracted with ethyl acetate, separated, dried over anhydrous sodium sulfate, filtered, and purified by flash column chromatography to obtain the pure product, and the yield was calculated to be 97%. NMR data: 1 1H NMR (400 MHz, CDCl3) δ 4.81 - 4.75 (ddt, J = 8.5, 6.1, 3.6 Hz, 1H), 4.47 - 4.43 (t, J = 8.4 Hz, 1H), 4.32 - 4.29 (dd, J = 8.4, 6.1 Hz, 1H), 3.61 - 3.57 (dd, J = 11.2, 3.4 Hz, 1H), 3.51 - 3.48 (dd, J = 11.2, 3.8 Hz, 1H), 3.35 (s, 3H).

[0105] Application Example 22: 0.5 mol% of L3Y2Cl3 catalyzed the cycloaddition reaction of n-butyl glycidyl ether and carbon dioxide at 90 °C under atmospheric pressure:

[0106] In a reaction flask that had been treated with anhydrous and anaerobic conditions and protected by an inert gas, 0.0039 g (2.19×10 -6 mol) of L3Y2Cl3 was added, and then 0.63 mL (4.38×10 -4 mol) of n-butyl glycidyl ether was injected with a syringe. After replacing all the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, the entire apparatus was stirred at 90 °C for 16 hours. After cooling to room temperature, 5 mL of deionized water was added to quench the reaction. The mixture was transferred to a separatory funnel, extracted with ethyl acetate, separated, dried over anhydrous sodium sulfate, filtered, and purified by flash column chromatography to obtain the pure product, and the yield was calculated to be 90%. NMR data: 11H NMR (400 MHz, CDCl3) δ 4.82 - 4.76 (ddt, J = 8.1, 6.2, 3.9 Hz, 1H), 4.50 - 4.46 (t, J = 8.3 Hz, 1H), 4.40 - 4.36 (dd, J = 8.3, 6.1 Hz, 1H), 3.68 - 3.64 (dd, J = 11.0, 4.0 Hz, 1H), 3.61 - 3.58 (dd, J = 11.0, 3.7 Hz, 1H), 3.52 - 3.48 (t, J = 6.5 Hz, 2H), 1.58 - 1.51 (m, 2H), 1.40 - 1.31 (dd, J = 15.0, 7.4 Hz, 2H), 0.92 - 0.89 (t, J = 7.4 Hz, 3H).

[0107] Application Example 23: 0.5 mol% of L3Y2Cl3 catalyzes the cycloaddition reaction of allyl glycidyl ether and carbon dioxide at 90 °C under atmospheric pressure:

[0108] In a reaction flask that has been treated for anhydrous and anaerobic conditions and is protected by an inert gas, 0.0039 g (2.19×10 -6 mol) of L3Y2Cl3 is added, and then 0.52 mL (4.38×10 -4 mol) of allyl glycidyl ether is injected using a syringe. After replacing all the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, the entire apparatus is stirred and reacted at 90 °C for 16 hours. After cooling to room temperature, 5 mL of deionized water is added to quench the reaction. The mixture is transferred to a separatory funnel, extracted with ethyl acetate, separated, dried over anhydrous sodium sulfate, filtered, and purified by flash column chromatography to obtain a pure product. The yield is calculated to be 98%. NMR data: 1 1H NMR (400 MHz, CDCl3) δ 5.88 - 5.79 (dq, J = 10.8, 5.6 Hz, 1H), 5.27 - 5.17 (m, 2H), 4.83 - 4.78 (td, J = 9.2, 3.7 Hz, 1H), 4.50 - 4.45 (t, J = 8.4 Hz, 1H), 4.38 - 3.34 (m, 1H), 4.06 - 3.98 (m, 2H), 3.69 - 3.65 (dd, J = 11.1, 3.7 Hz, 1H), 3.60 - 3.56 (dd, J = 11.1, 3.7 Hz, 1H).

[0109] Application Example 24: 0.5 mol% of L3Y2Cl3 catalyzes the cycloaddition reaction of propargyl glycidyl ether and carbon dioxide at 90 °C under atmospheric pressure:

[0110] In a reaction flask that has been treated for anhydrous and anaerobic conditions and is protected by an inert gas, 0.0039 g (2.19×10 -6mol) of L3Y2Cl3, and then 0.47 mL (4.38×10 -4 (mol) of propargyl glycidyl ether was injected with a syringe. After replacing all the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, the whole device was stirred at 90 °C for 16 hours. After cooling to room temperature, 5 mL of deionized water was added to quench the reaction. The mixture was transferred to a separatory funnel, extracted with ethyl acetate, separated, dried over anhydrous sodium sulfate, filtered, and purified by flash column chromatography to obtain the pure product, and the yield was calculated to be 75%. NMR data: 1 1H NMR (400 MHz, CDCl3) δ 4.85 - 4.81 (ddt, J = 8.5, 6.0, 3.6 Hz, 1H), 4.50 - 4.46 (t, J = 8.5 Hz, 1H), 4.36 - 4.32 (dd, J = 8.4, 6.0 Hz, 1H), 4.23 - 4.12 (qd, J = 16.0, 2.4 Hz, 2H), 3.77 - 3.73 (dd, J = 32.4, 11.0, 3.6 Hz, 1H), 3.69 - 3.65 (dd, J = 32.4, 11.0, 3.6 Hz, 1H), 2.48 - 2.47 (t, J = 2.4 Hz, 1H).

[0111] Application Example 25: 0.5 mol% of L3Y2Cl3 catalyzed the cycloaddition reaction of benzyl glycidyl ether and carbon dioxide at 90 °C under atmospheric pressure:

[0112] In a reaction flask that had been treated with anhydrous and anaerobic conditions and protected by inert gas, 0.0039 g (2.19×10 -6 (mol) of L3Y2Cl3 was added, and then 0.67 mL (4.38×10 -4 (mol) of benzyl glycidyl ether was injected with a syringe. After replacing all the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, the whole device was stirred at 90 °C for 16 hours. After cooling to room temperature, 5 mL of deionized water was added to quench the reaction. The mixture was transferred to a separatory funnel, extracted with ethyl acetate, separated, dried over anhydrous sodium sulfate, filtered, and purified by flash column chromatography to obtain the pure product, and the yield was calculated to be 96%. NMR data: 11H NMR (400 MHz, CDCl3) δ 7.32 - 7.22 (m, 5H), 4.75 - 4.69 (ddt, J = 8.4, 6.0, 3.6 Hz, 1H), 4.55 - 4.47 (q, J = 12.0 Hz, 2H), 4.39 - 4.35 (t, J = 8.4 Hz, 1H), 4.29 - 4.25 (dd, J = 8.4, 6.0 Hz, 1H), 3.65 - 3.61 (dd, J = 11.1, 3.4 Hz, 1H), 3.53 - 3.50 (dd, J = 11.1, 3.7 Hz, 1H).

[0113] Application Example 26: 0.5 mol% of L3Y2Cl3 catalyzes the cycloaddition reaction of phenyl glycidyl ether and carbon dioxide at 90 °C under atmospheric pressure:

[0114] In a reaction flask that has been treated for anhydrous and anaerobic conditions and is protected by an inert gas, add 0.0039 g (2.19×10 -6 moles) of L3Y2Cl3, and then inject 0.59 mL (4.38×10 -4 moles) of phenyl glycidyl ether using a syringe. After replacing all the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, stir the entire apparatus at 90 °C for 16 hours. After cooling to room temperature, add 5 mL of deionized water to quench the reaction. Transfer the mixture to a separatory funnel, extract with ethyl acetate, separate the layers, dry over anhydrous sodium sulfate, filter, and perform flash column chromatography to obtain the pure product. Calculate the yield to be 97%. NMR data: 1 1H NMR (400 MHz, CDCl3) δ 7.33–7.29 (m, 2H), 7.03 - 7.00 (t, J = 7.4 Hz, 1H), 6.92 - 6.90 (dd, J = 8.7, 0.9 Hz, 2H), 5.05 - 4.99 (ddt, J = 8.1, 5.9, 3.9 Hz, 1H), 4.63 - 4.58 (t, J = 8.4 Hz, 1H), 4.54 - 4.51 (dd, J = 8.5, 5.9 Hz, 1H), 4.25 - 4.22 (dd, J = 10.6, 4.1 Hz, 1H), 4.15 - 4.12 (dd, J = 10.6, 3.6 Hz, 1H).

[0115] Application Example 27: 0.5 mol% of L3Y2Cl3 catalyzes the cycloaddition reaction of 4-vinyl-1-cyclohexene dioxide and carbon dioxide at 90 °C under atmospheric pressure:

[0116] In a reaction flask that has been treated for anhydrous and anaerobic conditions and is protected by an inert gas, add 0.0039 g (2.19×10 -6mol) of L3Y2Cl3, and then 0.56 mL (4.38×10 -4 mol) of 4-vinyl-1-cyclohexene diepoxide was injected with a syringe. After replacing all the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, the whole device was stirred at 90 °C for 16 hours. After cooling to room temperature, 5 mL of deionized water was added to quench the reaction. The mixture was transferred to a separatory funnel, extracted with ethyl acetate, separated, dried over anhydrous sodium sulfate, filtered, and purified by flash column chromatography to obtain the pure product. The yield was calculated to be 40%. NMR data: 1 1H NMR (400 MHz, CDCl3) δ 4.49 - 4.22 (m, 2H), 4.17 - 3.89 (m, 1H), 3.12 - 3.02 (ddd, J = 30.0, 7.8, 3.3 Hz, 2H), 2.29 - 0.92 (m, 8H).

[0117] Application Example 28: 0.5 mol% of L3Y2Cl3 catalyzed the cycloaddition reaction of 2-(chloromethyl)-1,2-epoxypropane and carbon dioxide at 90 °C under atmospheric pressure:

[0118] In a reaction flask that had been treated anhydrously and anaerobically and was protected by an inert gas, 0.0039 g (2.19×10 -6 mol) of L3Y2Cl3 was added, and then 0.42 mL (4.38×10 -4 mol) of 2-(chloromethyl)-1,2-epoxypropane was injected with a syringe. After replacing all the inert gas in the reaction flask with an external airbag filled with carbon dioxide gas, the whole device was stirred at 90 °C for 16 hours. After cooling to room temperature, 5 mL of deionized water was added to quench the reaction. The mixture was transferred to a separatory funnel, extracted with ethyl acetate, separated, dried over anhydrous sodium sulfate, filtered, and purified by flash column chromatography to obtain the pure product. The yield was calculated to be 20%. NMR data: 1 1H NMR (400 MHz, CDCl3) δ 4.50 - 4.48 (d, J = 8.8 Hz, 1H), 4.16 - 4.14 (d, J = 8.8 Hz, 1H), 3.73 - 3.70 (d, J = 11.9 Hz, 1H), 3.60 - 3.57 (d, J = 11.9 Hz, 1H), 1.61 (s, 1H).

[0119] The above-mentioned embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. It can be seen from the above embodiments that the present invention uses a novel bis(aryloxy) functionalized imidazolium rare earth metal complex L3RE2Cl3 (H2LCl = 1,3-bis(3,5-di-tert-butyl-2-hydroxybenzyl)-imidazolium chloride, RE = Y, Yb, Sm, Nd, La) as a single-component catalyst to catalyze the cycloaddition reaction of epoxides with carbon dioxide. Among them, the structure of the catalyst bis(aryloxy) functionalized imidazolium rare earth metal complex L3RE2Cl3 is clear, the preparation is simple, and the yield is high. Under this system, the reaction conditions are relatively mild, the substrate adaptability is wide, no cocatalyst is required, and the target product can be obtained in excellent yield under the conditions of low temperature and normal pressure for monosubstituted epoxides with different substituents. The whole experimental process is simple to operate, easy to post-treat, and has high safety.

[0120] Obviously, the above embodiments are merely examples for clear illustration, and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. Use of a bis(aryloxy)-functionalized imidazolium rare earth metal complex in the catalytic cycloaddition reaction of epoxides with carbon dioxide, characterized in that, The rare earth metal complex of bis(aryloxy) functionalized imidazolium salt is obtained by reacting bis(aryloxy) functionalized imidazolium salt H2LCl with RE[N(SiMe3)2]3, and the structural formula is as follows: Among them, RE is yttrium, ytterbium, samarium, neodymium or lanthanum; the structural formula of the bis(aryloxy) functionalized imidazolium salt H2LCl is as follows:

2. The use according to claim 1, characterized in that, The rare earth metal complex of imidazolium salt is prepared by the following method: Dissolve RE[N(SiMe3)2]3 in an organic solvent to obtain a solution of RE[N(SiMe3)2]3, and dropwise add the H2LCl solution, react for 12 - 18 hours, and purify and concentrate to obtain the rare earth metal complex of imidazolium salt; where RE is yttrium, ytterbium, samarium, neodymium or lanthanum.

3. The use according to claim 2, characterized in that, The H2LCl in the H2LCl solution is prepared by the following method: Dissolve 2,4 - di - tert - butyl - 6 - chloromethylphenol in an organic solvent, add sodium bicarbonate and imidazole, react at 80 - 110 °C for 12 - 24 hours, after the reaction is completed, perform solid - liquid separation to take the solid phase, and thus obtain the H2LCl.

4. The use according to claim 1, characterized in that, The specific application method steps are as follows: Under an inert gas environment, add an alkylene oxide to the rare earth metal complex of bis(aryloxy) functionalized imidazolium salt, after introducing carbon dioxide gas to displace all the inert gas, stir and heat, after the reaction is completed, add a quenching agent to terminate the reaction, and obtain a cyclic carbonate compound.

5. The use according to claim 4, characterized in that, The molar ratio of the alkylene oxide to the rare earth metal complex of bis(aryloxy) functionalized imidazolium salt is 400 - 100:1.

Images